Building walls is pointless anyway since the raids spawn inside the settlement boundary. Any fortifications designed to protect against an attack from outside will fail, because the attacker magically appear right in the middle. When I realized that was why my defenses kept failing to keep raids out, I finally uninstalled the game.
I would have liked to like Fallout 4. Honestly, I really did want to. I wanted to be pleasantly surprised because it was, on paper, exactly what I was looking for. The ruins of a post-apocalyptic city, with plenty of exploration and verticality. Shootouts with raiders as I fight my way up a ruined skyscraper. Customize weapons and armour. Build myself a base how I want. If it were done well, I would sink hundreds of hours into it.
But in all elements, it is utterly awful at worst and merely mediocre at best. Even when you ignore primarily-RPG elements like quests, stats, or even dialogue (despite these elements being relevant to non-RPGs as well), it still fails.
The optimization is trash. Even as poor as the graphics are (pic 1), the game still struggles. I often dipped below 20fps, even when I lowered settings. And in case of any mocking cries of "muh grafix", I do not mean the graphics were unrealistic, I mean they were bad. Things were ugly, texture seams were obvious, distorted textures, and so on. With FPS combat, where I am directly encouraged to be in positions like pic 1, you cannot make excuses that I'm looking too close; the gameplay makes such examination very common even when you aren't looking for it intentionally.
Gunplay was improved over 3, yes. It was enough that I have no major gripes in that regard. But combat was still bad because of the enemies. AI was so poor that I had to actively try to NOT cheese many enemies. Deathclaws would be excellent and terrifying encounters, were it not for the fact I more often than not accidentally backed through a doorway while running and ended up out of reach. Enemies could also be annoying with bullet-sponginess, and there was no way to fix it. Increasing player damage made raiders too trivial, but not doing so made other enemies (like super mutants) incredibly spongy. Even when I installed a mod to increase PC and NPC damage by 350%, it still took more than a full mag from a maxed-out combat rifle to kill the lowest level of mutant, and such a high damage increase was entirely impractical for many other encounters.
And the guns themselves sucked. Unique weapons were essentially non-existent, being mostly reduced to instances of the Legendary system. Weapon diversity was minimized because of the customizability - which did not actually make up for the limited selection, because it was mostly a direct progression instead of compromise and specialization. Designs were terrible (such as the assault rifle or pic 2), and others had obnoxious oversights (left-handed hunting rifle, with the associated animations drawing attention to it every single shot).
Base building sucked. Most of the area of most settlements was unusable because Bethesda insists on everything being broken and covered in debris. There is no reason I can tear down one Sanctuary house but not the one next to it, especially when I am also not allowed to patch the giant fucking holes in the ceiling. And even the mods to let you clean up don't work, because the line-of-sight rendering still thinks the garbage is there and stops showing the terrain behind it. Hell, in some cases they forgot to make parts of the terrain buildable. You can only build on the top level of the Greygarden overpass with a combination of console, luck, and the autism to waste your time finding exactly the right alignment. The settlers for all intents and purposes do not exist. I had to set specific clothing to different roles to even tell them apart, since they don't have names. Attacks are meaningless and lazily implemented.
And when all this is combined with the stillborn modding community, it will never get fixed either. I don't see why this game is worth playing, no matter what you're looking for.